Specific immunologic antisera directed against the total proteins of the 40S (TP40) and 60S (TP60) ribosomal subunits of cultured Chinese hamster cells will be raised in rabbits and in goats. Additionally, mouse antisera directed against individual 40S ribosomal proteins purified by 2-D PAGE will be prepared, and spleen cells from responding mice will be used to generate cloned hybridoma which secrete monospecific IgG. These reagents together with 2-D PAGE will be used to analyze ribosomal subunit structural proteins in wild type and several Chinese hamster cell clones which possess either drug-resistance or temperature-sensitive mutations affecting their ribosomes' structure and function. The immunologic reagents also will be used to examine translational and post-translational control mechanisms which insure that the 75 ribosomal proteins are synthesized by animal cells in stoichiometrically equivalent amounts. Peptides from S14 proteins purified from 40S ribosomal subunits of wild type and mutants resistant to the alkaloid drug emetine (Emr) will be ordered into an amino-to-carboxy sequence and will permit the "fine-structure" mapping of the Emr (S14) gene of Chinese hamster cells. Also banding patterns of chromosomes from Emr mutants, Emr/Ems tetraploid hybrid clones and Emr-segregants derived from hybrids will be studied to locate the Emr (S14) locus within the Chinese hamster cell karyogram.